Broker not Responding occasionally

We are running webMethods version 6.1 and are experiencing an issue on an inconsistent basis.

We are publishing documents to broker using service. 95% of published docs return a Reply as expected. However, this other 5% is timing out, it’s not receiving a response from the broker. The Backend service that subscribes to these documents is logically ordered to always return a Reply (even if error occurrs).

I thought I might find the problem with maximum server/error logging enabled. However, I see no errors or indication of why this 1% of requests are failing.

In effort to resolve the problem we deleted document types from Broker and resynced the docs, but that did nothing.

I’m wondering if anyone has ever experienced this issue. Any ideas? Thank you.

Here’s the publishAndWait parameters

So, what did you want to happen if the client had to wait for longer than 30 seconds?